var duration : float= 1.0;
function Update() {
	if(particleEmitter.emit)
	{
		// argument for cosine
		var phi : float = Time.time / duration * 2 * Mathf.PI;
		// get cosine and transform from -1..1 to 0..1 range
		var amplitude : float = Mathf.Cos( phi ) * 0.5 + 0.5;
		// set light color
		light.intensity = amplitude*2;
	}
	else
	{
		light.intensity = 0;
	}
}